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...--------------______________________________________ M. Ashraf Chaudhary, Ph.D. Associate Scientist/Biostatistician Department of International Health Johns Hopkins Bloomberg School of Public Health 615 N. Wolfe St. Room W5506 Baltimore MD 21205-2179 (410) 502-0741/fax: (410) 502-6733 <mailto:mchaudha@jhsph.edu> mchaudha@jhsph.edu Web:http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary [[alternative HTML version deleted]]

...eciate your pointing me to the source of the problem. Ashraf _________________________________ M. Ashraf Chaudhary, Ph.D. Department of International Health Johns Hopkins Bloomberg School of Public Health 615 N. Wolfe St. Room W5506 Baltimore MD 21205-2179 (410) 502-0741/fax: (410) 502-6733 mchaudha@jhsph.edu <mailto:mchaudha@jhsph.edu> [[alternative HTML version deleted]]

I am trying to find out if R can recognize specific criteria for removing rows (i.e. a prexisting function) I have a matrix myMatrix that is 12000 by 20 I would like to remove rows from myMatrix that have: -999 across all columns -999 across all columns but one -999 across all columns but two -999 across all columns but three -999 across all columns but four -999 across all columns but five

...___________________________________ M. Ashraf Chaudhary, Ph.D. Associate Scientist/Biostatistician Department of International Health Disease Prevention and Control Program Johns Hopkins University Bloomberg School of Public Health 615 North Wolfe Street, Room W5506 Baltimore MD 21205 mchaudha@jhsph.edu Phone: (410) 502-0741/Fax: (410) 502-6733 http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary [[alternative HTML version deleted]]

I am producing 2X2 correlation matrices by a class variable. I need to extract a vector of correlation coefficients only. I am doing that in a loop (see below) but I am sure there would be a simpler way. Please help! > by(d1[,c(2,3)],d1[,1],cor) d1[, 1]: 1 c e c 1.0000000 0.1972309 e 0.1972309 1.0000000

...atch2) -----------------______________________________________ M. Ashraf Chaudhary, Ph.D. Associate Scientist/Biostatistician Department of International Health Johns Hopkins Bloomberg School of Public Health 615 N. Wolfe St. Room W5506 Baltimore MD 21205-2179 (410) 502-0741/fax: (410) 502-6733 mchaudha at jhsph.edu Web:http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary

...me with 0 rows _________________________________ M. Ashraf Chaudhary, Ph.D. Assisociate Scientist/Biostatistician Department of International Health Johns Hopkins Bloomberg School of Public Health 615 N. Wolfe St. Room W5506 Baltimore MD 21205-2179 (410) 502-0741/fax: (410) 502-6733 mchaudha@jhsph.edu Web:http://faculty.jhsph.edu/?F=Mohammad&L=Chaudhary [[alternative HTML version deleted]]

Hi All: I would like to generate a binomial random variable that correlates with a normal random variables with a specified correlation. Off course, the correlation coefficient would not be same at each run because of randomness. I greatly appreciate your input. Ashraf

Hi All; The following question is directed more to statisticians on the list. Suppose I have a normal random variable. Is there a transformation that I can apply so that the new variable is slightly positively skewed. I greatly appreciate your help. Ashraf